Elmer's Wobbler #25

[Propforward]

Your diagram is correct.

 

[Apprentice]

Your diagram is correct.

Cheers prop

 

[thayer]

Yes, although with the piston in that position my guess is the inlet port would have already been closed.

 

[Apprentice]

CAD so far -



I was thinking of having a vertical osilliator - I have found some designs for this on the net. Or perhaps I could scale Elmer's units up to the nearest whole figure.

Next step (re-egineering)


During my CAD, I noticed the Shaft Bush was slightly over, I had to reduce the dimension by 1.16mm, to ensure the piston and rod fit within the cylinder and connect to the crankshaft pin correctly.

 

[Propforward]

Nice work there - but I notice that your pivot hole is still being machined from the wrong side of the frame. The counterbore should be the other side to the cylinder.

What solid modelling program are you using out of interest? Is it solidworks?

 

[Apprentice]

Yes, although with the piston in that position my guess is the inlet port would have already been closed.

Cheers Thayer - I have ammended this on my report

 

[Apprentice]

Nice work there - but I notice that your pivot hole is still being machined from the wrong side of the frame. The counterbore should be the other side to the cylinder.

What solid modelling program are you using out of interest? Is it solidworks?

Perhaps its the CAD Platform I am using potrays this differently? Solidworks. I have ensured the countrebore is on the opposite side to cylinder.

 

[Propforward]

But your bottom diagram shows a counterbore as well - I think that surface should just be a plain hole, otherwise flush to the cylinder. I'm going from memory (often a bad idea), I'll have to check.

Your top diagram looks like a countersink to me rather than a counterbore.

EDIT: Yes, the original Elmer plan calls for a through hole on the cylinder side of the frame, with the counterbore on the other side, which is what holds the compression spring in place. I don't think the way you have it would be a problem as such, but the counterbore in the bottom image of the previous post doesn't actually do anything.

Very nice execution of the solid model though. CAD is an artform of its own in my opinion.

 

[Apprentice]

Oh! My tutor has just specified what exactly you mean - I guess I'll have to get back to it after the Holidays! Cheers for the heads up Prop.

Enjoy your Christmas everybody!

 

[Propforward]

Cool! Merry Christmas, and enjoy your holiday!

 

[gjrepesh]

Here's a picture of the Wobbler I made for my nephew's son. I mounted it on purple heart wood. It was a birthday gift and I included a small air compressor as well as a booklet of the construction with photos. A fun project. Gary R.

 

[thayer]

Very nicely done Gary. It looks like a wonderful present.

 

[Apprentice]

Hello Guys,

Was wondering if anybody had any information concerning material selection for the wobbler components?

Gary - nice wobbler mate.

 

[Brian Rupnow]

Aluminum for all body parts, mild steel (cold rolled) for the shaft, brass or bronze for the flywheel and cylinder. Aluminum for the piston. The flywheel can also be made from mild steel.

 

[Apprentice]

any particular reason as to why those materials?

 

[Apprentice]

Previous to this thread, whilst I was searching through other threads - I came across a table; I believe this was like a material comparison table.

But I cannot seem to find it now

 

[Brian Rupnow]

Because---Aluminum is comparitively cheap and very easy stuff to machine compared to steel. Brass is expensive as Hell, but can be polished up very nicely for some "Bling",and it too machines a lot easier than steel.

 

[Apprentice]

Because---Aluminum is comparitively cheap and very easy stuff to machine compared to steel. Brass is expensive as Hell, but can be polished up very nicely for some "Bling",and it too machines a lot easier than steel.

Cheers Brian

Is there any particular type of steel, brass or aluminum that I should be comparing e.g alloy 2007 aluminim etc?

 

[Brian Rupnow]

6061 for aluminum. Don't know for sure about brass. I just buy what my local supplier has available in bar or round stock, but I've never asked about a grade for it.

 

[rleete]

For brass, get 360 free machining. Other grades are a little cheaper, buy 360 is so much easier to cut that it's worth it.


Edit:
Oh and try some 2024 series aluminum if you get the chance. It's great stuff to work with